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Core Concept

ConVoid creates openings wherever a Reference Element (the element that needs to pass through) intersects a Host Element (the element that receives the opening). Reference and host elements can live in your active project or in a linked Revit or IFC model.

Three workflows are available, each tailored to a specific role and a specific source of reference elements. Choosing the correct workflow up front avoids issues later in the project.

The Three Workflows​

A
Create Openings
For MEP engineers
  • Reference elementsDucts, pipes, cable trays (your model or linked)
  • Host elementsWalls, floors, beams, roofs
  • ResultGeneric ConVoid openings (rectangular or circular)
  • Use it whenYou design the MEP services and need openings for your own systems.
Go to Workflow A
B
Adopt Openings
For architects and structural engineers
  • Reference elementsProvision for Voids from a linked Revit or IFC model
  • Host elementsWalls, floors, beams in your project
  • ResultGeneric ConVoid openings linked to the source PfV
  • Use it whenAnother discipline has placed openings (PfV) and you need them in your model.
Go to Workflow B
C
Create Structural Openings
For structural engineers
  • Reference elementsDoors and windows from a linked architectural model
  • Host elementsStructural walls in your project
  • ResultFace-based structural opening families (Door / Window)
  • Use it whenYou need wall-hosted openings that follow the architect's doors and windows.
Go to Workflow C

Model Requirements​

ConVoid works with all Revit and IFC elements that are represented as 3D geometry, regardless of category. The model must meet two requirements.

Requirement 1: At Least One Clash​

There must be at least one valid intersection between a reference element and a host element. Examples of valid clashes include:

  • A duct penetrating a wall
  • A pipe passing through a floor
  • An IFC Provision for Void intersecting a beam
  • A door placed in a wall
  • A generic element clashing with a roof

Requirement 2: Stay Within Revit's Distance Limit​

Revit becomes graphically unreliable when geometry is located more than 16 km (10 miles) from the model's internal origin. ConVoid may not be able to place openings accurately in these areas.

Models Far from Origin

If ConVoid shows the error "The input point lies outside of Revit design limits", your model (or a linked model) is too far from the internal origin and needs to be repositioned.

For more details on this Revit limitation, see Autodesk's documentation on design limits.

Limitations​

Project and Model Size​

There are no hard limits on project or model size. ConVoid is used successfully in large-scale projects with up to 50,000 openings in a single model. For optimal performance, create and update openings step by step rather than processing the entire model at once.

Performance Recommendations for Large Projects

For projects with many openings or large linked models, follow these strategies:

  • Split by discipline: process ductwork, piping, and cable trays separately using dedicated filters.
  • Split by level: focus on one or a few levels at a time.
  • Split by zone: create a 3D view per building zone and configure ConVoid to process only that view.
  • Batch size: aim for approximately 2,000 openings per processing run.
  • Highly detailed elements: heavily meshed 3D objects can extend calculation times.